About : BIRT JPA or JDO Connector

Abstract

The Java Persistence API (JPA)is the Java API for the management of persistence and object/relational mapping for Java EE and Java SE environments. The persistence consists of three areas:

the API, defined in the javax.persistence package
the Java Persistence Query Language
object/relational metadata

The purpose of this project proposal is to implement a Connector JPA for BIRT framework, and so able to handle data source from the persistence API. Is so great the importance of the project because JPA is a specification that is being used widely in the development of applications, precisely from the advantages it.

The implementation is to make the JPA ODA driver, extending each one of the interface required in the Data Tools Plataform given in the package org.eclipse.datatools.connectivity.oda.

Finalizing it first part will be an improvement approaching also advanced options in regard to the parameters and also will be implemented JPA ODA IU extensions.

Participants

Student: Victoriano Alfonso Phocco Diaz <vphocco@gmail.com> -

http://alfonso777.blogspot.com/

Student: Jorge Fabian Chuquitaype Zuñiga <jfabianchz@gmail.com>
Mentor: Jason Weathersby <jweathersby@actuate.com> - http://www.blogger.com/profile/13114050439576571984 http://eclipse.sys-con.com/author/jasonweathersby.htm
Project Hosting GSoC:

http://code.google.com/p/birt-jpa-connector/

Planned Features

Handling of configuration file: persistence.xml.
JPA utilities for get current EntityManager and EntityManagerFactory
JPQL queries validation.
Get the metadata information such as column names, column types, column class for the query .
Instantiation of ResulSetMetaData, DataSetMetaData, ResulSet.
Soport in the preparement and execution of Queries.
Working good with the implementations de JPA: Hibernate and TopLink.

Should Have

Handling of other configuration file: orm.xml
Soport more advance of Parameters into queries.

Nice to have

Soport JDO and JPA at the same time.

Community proposals

Feel free to add your comments and ideas.

Getting the source

ViewCVS: http://code.google.com/p/birt-jpa-connector/source/browse [1]

CVS: https://birt-jpa-connector.googlecode.com/svn/trunk/

Getting Resources

Here you get examples, examples and test for some modules. Moreover there are scripts for DB, JPA example, screenshots, videos demo , etc.

http://code.google.com/p/birt-jpa-connector/downloads/list

JPA ODA plugin

Source Code

http://code.google.com/p/birt-jpa-connector/source/browse/#svn/trunk/org.eclipse.birt.report.data.oda.jpa

The "Statement" class

The "Statement" class, prepare the result set metadata of the query (containing column name, column type, and entity name that belong), execute the query, and fetches the data rows from the Data Source.

Problems founded developing whit JPA in this class:

1. To get attributes of the entities (field names and field types) found into the query e.g.:

SELECT d.departmentIdentifier, d.name 
FROM Department d

Was necessary know the complete path, like “jfabian.model.department.entity.Department”, an option was write this in the query as is possible in hibernate but this idea was discard becouse JPA not allow it.

The solution was getting the name of entity and searches the complete path into “persistence.xml” file, this implemented in “JPAUtil.findEntityOnPersistenceXML(entityName, classNodes)” function.

2. Other aspect to take into consideration are the entity alias, this to retrieve the corresponding column e.g.:

SELECT d.departmentIdentifier, d.name, 
e.employeeIdentifier  , e.firstName
FROM Department d, Employee e

In this query the alias for Department is “d”, and its columns are “departmentIdentifier” and “name”, to retrieve the columns types I need know the entity name (with path complete), and column or field name.

And the functionality should be correct if the column order is not the same to instance of the entities, e.g.:

SELECT e.firstName, d.name, 
e.employeeIdentifier, d.departmentIdentifier
FROM Department d, Employee e

For this task was implemented “extractColumns(qry)”, that return a “List<List<String>>” containing the entity alias and column name. Other was “getReturnEntities( String query )”, that return a “List<List<String> >” containing entity name and entity alias.

Work future

A) Yet not support the recognition of alias with “as” like:

SELECT d.name FROM Department as d

B) Yet not support retrieve all columns of the entity (similarity to Selec *from department in JDBC):

SELECT d FROM Department as d

C) When a entity has a member variable to other entity, retrieve its metadata still is not possible:

SELECT d.director.firstName FROM Department d

In this case “director” is an entity “Employee”

D) Yet not distinguish some reserved words like:

SELECT DISTINCT d.name FROM Department d

E) Collection member declaration*

SELECT DISTINCT l.product FROM Order AS o, IN(o.lineItems) l

F) The possibility for retrieve metadata when use aggregate functions *

SELECT AVG(mag.price) FROM Magazine mag

On JSR220: Enterprise Java Beans V3.0, Java Persistence API in Chapter

Video Demo

In this video we are preparing all necesary for generate the report, like; install BIRT Runtime, deploy the ODA JPA plug-in, create the JPA test project, install the Sample database, configure the report, etc.:
- http://www.puntoevolucion.com/GSoC/preparing_all.htm

Here show the generation of report and the result:
- http://www.puntoevolucion.com/GSoC/Generating_Report_from_ODA_JPA.htm

Screenshots

http://birt-jpa-connector.googlecode.com/files/ScreenShots%20-%20JPA%20ODA%20UI.rar

New JPA Project for example
Specify Driver and Connection
Generating Entities from Tables
Editing persistence.xml with Toplink implementation
Establishing APP_JPA and PERSISTENCE_UNIT properties in new_report_jpa.rptdesign
Establishing Query
Testing report with JPA ODA plugin
Show Results(I)
Show Results(II)
Viewing Report generated in Browser

JPA ODA UI Plug-in

Source Code

http://code.google.com/p/birt-jpa-connector/source/browse/#svn/trunk/org.eclipse.birt.report.data.oda.jpa.ui

Description

To use the data retrieved by the JPA ODA driver in a BIRT report design, One must extend the DTP design UI. To implement the JPA ODA UI, extend the following extension points:

org.eclipse.datatools.connectivity.oda.design.ui.dataSource
org.eclipse.ui.propertyPages
org.eclipse.datatools.connectivity.connectionProfile

Video Demo

Screenshots

Test Launching oda-jpa-ui
New JPA Data Source
Select JPA application directory
Insert Persistence Unit Name
New JPA Data Set
Enter and Verify JPQL Query
Output Columns of JPA Data Set
Preview Results of JPA Data Set
Attributes Visualization of JPA Data Set
Drag and Drop
Output Console in oda-jpa

References

BIRT References

Eclipse Resources:

http://www.eclipse.org/resources/?category=BIRT

The plug-in extension examples from Integrating and Extending BIRT

http://www.actuate.com/products/products-resources.asp?ArticleId=11719

http://birtworld.blogspot.com/
http://eclipse.sys-con.com/author/jasonweathersby.htm
Book:Jason Weathersby, Don French, Tom Bondur, Jane Tatchell, Iana Chatalbasheva, "Integrating and Extending BIRT",Addison-Wesley.